Skewed sex composition is believed to be a reflection of gender-based unequal treatment by the families and society at large. The child Sex Ratio (CSR)-the ratio of girls to boys in the age group of 0-6 years, is a telling indicator of social well-being. The trend of increasing masculinisation of child population in different parts of India has become a cause of worry and concern. This paper analyses the pace, geography and causes of deteriorating child sex Ratio in Odisha. Findings reveal that though Odisha has registered a slight improvement in overall sex ratio between 2001 and 2011, the gap between genders below the age of six has begun widening considerably. Geography of declining child sex ratio indicates that epicentres of low child sex ratio have expanded spatially. The pace of decline is sharper in urban pockets in comparison to rural areas. The downward trend is an indication of female foeticide and higher mortality rate among girl children. The situation is going to worsen in the future in the light of diffusion of sex-detection technologies to the rural and tribal areas.